Draft-free integral door unit



July 18, i967 A. J. GLADD ETAL 3,331,303

DRAFT-FREE INTEGRAL DOOR UNIT Filed June l5, 1966 INVENTORS BY zzazen/ J Glan/d zffe/ /Z Henson, 5

United States Patent 3,331,303 DRAFT-FREE INTEGRAL DOOR UNIT Andrew J. Gladd, Farmington, and Artel R. Henson, Birmingham, Mich., assignors to Disco Engineering, Inc., Detroit, Mich., a corporation of Michigan Filed June 13, 1966, Ser. No. 557,149 3 Claims. (Cl. 98-36) This invention relates to air curtain doors in general and more particularly to a construction which is freestanding and has a normal door closure incorporated as a part thereof.

Air curtain doors as commonly known are simply ductwork provided near a doorway opening or the like and capable of directing a curtain of air across the opening. A great `deal of expense is involved in installation and the improvements become part of the building structure and must be amortized out with the building costs.

It also becomes expensive to make any changes after installation to meet different requirements.

It is an object of this invention to provide a freestanding structure which incorporates all of the features necessary for an air curtain door and which is relatively simple to manufacture, and therefore less expensive, and which may be readily adapted for installation and use within ahnost any door opening or the like. Further, the free-standing structure includes means for providing a normal door closure in combination therewith and in a manner which makes the air supply means still available for use, if and to the extent desired.

The free-standing unit of this invention makes use of fresh air, drawn in from the outside, provides means for heating and filtering the air, and is in all respects free and independent as regards other air conditioning, heating or like facilities of the building with which it is used. It constantly draws on and uses fresh air and does not re-circulate any of the air which provides the air curtain. In this respect, it is therefore capable of providing make up air, pressurizing a building to avoid insulation losses, and supplementing the needs of a building where desired. Since many buildings use indirect heating systems, and must exhaust flue gasses, an appreciable amount of air is lost and a negative pressure condition exists. The present system provides the ideal balance for otherwise deficient heating systems in this respect.

From the foregoing it will be appreciated that an ideal use of the present invention is in car and truck washing facilities where doors are often required to be kept open at opposite ends of a building for extended periods 'of time. Many available buildings can be easily used 4for this type of business since the unit proposed provides everything needed. Further, the air curtain provides a perfect stripping action for excess moisture following the final wet dry procedures.

In the description which follows, and from what has been said, numerous objects and advantages to be gained in the practice of this invention and distinctions over like but different structures will be more apparent.

In the accompanying drawings:

FIGURE l is a front elevation of a building entrance incorporating the free-standing unit of this invention therein and having an overhead door closure, not shown in this View.

FIGURE 2 is a top plan view of the free-standing unit by itself.

FIGURE 3 is an enlarged cross-sectional view as taken in the plane of line 3-3 of the previously mentioned drawing figure.

FIGURE 4 is a further enlarged cross-sectional view of one of the free-standing columns and shown to include the plenum chamber.

3,331,303 Patented July 18, 1967 The air curtain free-standing structure 10 is shown in the door opening 12 of a building 14 in the first drawing figure. It includes the supporting columns 16 and 18, and an overhead rectangular sectioned chamber member 20. The parts are fitted to the opening 12 and are received therewithin as best shown in the second drawing figure.

The supporting columns 16 and 18, and the chamber member 20 carried on them, are made of sheet metal. They may accordingly be made longer, with extensions or originally, and be cut or made shorter as different installations require. They may be secured to the side walls of the building framing the entrance but derive no support from such Walls.

The overhead chamber member 20 has one or more large blower units (not shown) mounted therein and such air filtering equipment or otherwise as required for a particular installation. It is provided with a fresh air intake opening, covered by t-he louvered screen 22, and such access doors 23 as may be desirable. A gas fired or other heating unit may be mounted in or connected to the overhead chamber member as indicated by the heatign unit enclosure 24.

Basically, the overhead chamber member receives fresh air through the centrally disposed intake opening and distributes it to opposite ends where it passes into the support columns 16 and 18.

The support columns are rectangular in shape with a stepped shoulder 26 formed on the adjacently disposed inner sides of each thereof and exposed to the inside of the building for which the unit is intended. It will be appreciated that the stepped shoulder 26 adds structural strength to the support columns and that essentially no other bracing or support is required.

Suitable studding may be provided right on the stepped shoulders of supports 16 and 18, as by the vertical studs 28 and cross member 30, right in the open arch formed by the supports and the overhead chamber member. The cross member 30 serves as a brace for a drop screen 32 of any desired width to reduce the open arch area and none of the studding is actually visible from the outside. The drop screen 32 may be of wood frame and sheet metal construction and is fastened to the overhead chamber member. It provides no bracing or support for the unit and is principally to reduce the opening height, as mentioned, and to accommodate the overhead door 34 yet to be described.

The support columns are formed to provide the plenum chambers 36 and 38 which receives heated or otherwise conditioned fresh air from the overhead chamber member 20. To this extent, there is an open communication between the columns and the overhead member and the blower means used is selected to move suicient air to pressurize the columns for purposes of providing the air curtain.

Both columns 16 and 18 are formed to include an air exhausting slot 40 which extends substantially their full length; that is, the length of the columns exposed below the drop screen 32. Such slots are formed by inwardly disposed walls 42 and 44 with the latter joined to the inner side wall of the supports to form a box brace 46. The slot forming walls 42 and 44 project sufficiently into the support columns to provide some baffling and restriction of the air to be exhausted through the slots 40 for best velocity effect.

It is the pressurized air in the columns 16 and 18 which is exhausted through the slots 40 that provides the air curtain indicated by the arrows in the open arch of the structure in the first drawing figure.

It will be appreciated that the air exhausted from each support column is directed straight across the archway towards the other column. It is not directed out of the |building nor is it directed into the building. However, as

the air streams come together there is a natural deflection and such air as is needed to replenish any deficiency in the building will be drawn and otherwise directed into the building for such purpose. Should the building be adequately pressurized, the air curtain air will be dispersed outside.

Referring now more closely to FIGURES 3 and 4:

The principal studs 28 on the stepped shoulders 26 of the columnar supports carry brackets 48 on which is supported guide rails 50 for the overhead door 34. They extend inside of the exhaust slots 40 and the arcuate and rearwardly extending parts are behind the drop screen 32.

The overhead door 34 is of the sectioned and articulate type and includes the usual brackets 52 and guide followers 54. When the door is open it is hidden behind the drop screen 32 and is up and completely out of the way. When it is closed it lies as shown in the third drawing figure, in front of the air curtain slots 40 and in closing engagement with the cross member 30 on the drop screen 32.

The significance of having a regular door closure provided with and on the air curtain structure is not to be viewed lightly. It is not normal, easy to accomplish or readily apparent that several advantages are obtained in doing so.

Some type of permanent closure is needed for all buildings. It is normally part of the permanent building structure and all air curtain structures heretofore have had to be designed and made to accommodate door closures of one kind. or another. This often precludes placing the air curtain structure in the best location or requires that the door unit be re-hung elsewhere. The most logical relocation is inside or outside of the air curtain structure with the consequent loss of advantage or greater exposure of the air curtain structure to inclement weather and such.

Most door frames are required to be of such sturdy construction that providing them inside of an air curtain structure would not be considered. This would also reduce the door opening and require greater capacity in the air curtain structure than would otherwise be necessary.

The present installation solves these problems by internal strengthening in the support columns 16 and 18 in the way they are formed and made. The stepped shoulders 26 serve not only to carry the door structure but as part of the strengthening which enables the columns to do so. They also provide corner support for the studs that carry the guide rails for the door and preclude the possibility of racking which would normally be expected with any frame construction fastened to sheet metal.

Although other than overhead doors may be used, the overhead door is ideally suited for use with the free-standing air curtain structure since it is completely removed from interference with the functional aspects of the air curtain system. In addition, in partly open or closed positions the air curtain may still be 4used effectively.

Without further discussion, it will be appreciated that certain modifications and foreseeable changes are envisioned within what has been set forth. Such of these are within the scope and spirit of this invention are to be considered so inclusive within the hereinafter appended claims. All uses and advantages of the structure disclosed, 4for car washes and otherwise, are to be considered as contemplated and only the specific language of the claims `shall be construed as imposing any negative limitations.

We claim:

1. An air curtain structure, comprising;

a pair of free-standing support columns made of sheet metal and formed to include a chamber enclosing rectilinear column having substantially no external bracing,

said columns including a stepped shoulder on one side face thereof and having a slot extending substantially the length thereof in said side face and with the side walls thereof projecting into said slot,

one of the inwardly projecting side walls being formed back on itself to provide a box brace and being spaced from said stepped shoulder,

a fresh air supplying chamber area member received over and wholly supported on said vfree-standing colums, as received under relatively opposite ends thereof, and in air supplying communication with the chamber space within said columns,

and a door closure received and supported on said `stepped shoulders for opening and closing the space bounded by said columns and overhead member,

said slots being adapted to exhaust air under pressure to provide an air curtain screen across and between said support columns when said door closure is open.

2. The air curtain structure of claim 1 said door closure including an overhead opening articulated door having guide tracks provided within said -step shoulder.

3. The air curtain structure of claim 2, including;

means within said chamber area member for inducting fresh outside air, conditioning said air as by heating it, and pressurizing said air in the course of supplying it to said columns,

said guide tracks being provided on the shoulders of the columns in front of the air curtain providing slots Iand extending rearwardly relatively thereover and below said air chamber member for supporting said door in front of said slots when closed and relatively thereover when open,

and a closure member extending between said columns from and below the chamber area member for closing the overhead space in which said door is accommodated when open yand for engagement with the overhead door when closed for enabling a pressurized exhaust therebehind.

References Cited UNITED STATES PATENTS 2,827,266 3/1958 `Ruif 98-36 X 3,038,400 `6/1962 Ruff 98-36 3,218,952 11/1965 Gygax 98-36 3,270,655 9/1966' Guirl et al. 98-36 ROBERT A. OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner. 

1. AN AIR CURTAIN STRUCTURE, COMPRISING; A PAIR OF FREE-STANDING SUPPORT COLUMNS MADE OF SHEET METAL AND FORMED TO INCLUDE A CHAMBER ENCLOSING RECTILINEAR COLUMN HAVING SUBSTANTIALLY NO EXTERNAL BRACING, SAID COLUMNS INCLUDING A STEPPED SHOULDER ON ONE SIDE FACE THEREOF AND HAVING A SLOT EXTENDING SUBSTANTIALLY THE LENGTH THEREOF IN SAID SIDE FACE AND WITH THE SIDE WALLS THEREOF PROJECTING INTO SAID SLOT, ONE OF THE INWARDLY PROJECTING SIDE WALLS BEING FORMED BACK ON ITSELF TO PROVIDE A BOX BRACE AND BEING SPACED FROM SAID STEPPED SHOUDLER, A FRESH AIR SUPPLYING CHAMBER AREA MEMBER RECEIVED OVER AND WHOLLY SUPPORTED ON SAID FREE-STANDING COLUMS, AS RECEIVED UNDER RELATIVELY OPPOSITE ENDS THEREOF, AND IN AIR SUPPLYING COMMUNICATION WITH THE CHAMBER SPACE WITHIN SAID COLUMNS, AND A DOOR CLOSURE RECEIVED AND SUPPORTED ON SAID STEPPED SHOULDERS FOR OPENING AND CLOSING THE SPACE BOUNDED BY SAID COLUMNS AND OVERHEAD MEMBER, SAID SLOTS BEING ADAPTED TO EXHAUST AIR UNDER PRESSURE TO PROVIDE AN AIR CURTAIN SCREEN ACROSS AND BETWEEN SAID SUPPORT COLUMNS WHEN SAID DOOR CLOSURE IS OPEN. 